Getting an image down to 20KB feels impossible when your phone photos are 5MB — that's a 250x reduction. The good news: with the right approach the result can still look perfectly acceptable, especially for the passport-style photos that usually need this size.
Why 20KB is hard
File size is driven by two things: the number of pixels (dimensions) and how aggressively those pixels are compressed. To reach 20KB you almost always need to reduce both. Lowering quality alone on a full-resolution photo produces ugly blocky artefacts; resizing first is the secret.
The reliable method
- Crop the photo to just what you need (e.g. head and shoulders).
- Resize the longest edge down to around 600–800 pixels — plenty for a small photo.
- Export as JPG and let a target-size tool fine-tune the compression to fit 20KB.
Our Reduce Image to 20KB tool automates steps 2 and 3 — it intelligently downsizes and runs a quality search until your image fits under 20KB, in seconds.
When you can't avoid some quality loss
For a detailed landscape or a busy group photo, 20KB is genuinely tiny and some softness is unavoidable. If the form allows it, prefer 50KB or 100KB for noticeably better clarity. But for the simple ID photos that usually require 20KB, the result is more than good enough.